Is it cheating?

I would like to know your opinion.

Questions related to chess online.

1. If your opponent consults with other players on Skype. Is it cheating?

2. If one players nickname  uses another stronger player, which you easily wins. Is it cheating?

3. If you know exactly what your opponent uses the engine in the game, and you have also decided to use the program against it. Is it cheating?

4. If the board played an absolute a draw but the opponent does not accept a draw, and makes 150 super-fast moves that you ran out of time. Is it cheating?